The present invention relates to an apparatus for controlling an elevator under a distributed control by a plurality of microcomputers and, more particularly, to an apparatus for controlling an elevator which eliminates a regulating unit.
A plurality of microcomputers are employed in an apparatus for controlling an elevator in accordance with the recent development of microelectronics.
Two microcomputers are employed in a conventional apparatus for controlling an elevator disclosed, for example, in Japanese Patent Application No. 59-77798 specification (Japanese Patent Application Laid-open No. 60-223,771), wherein one of the microcomputers has a sequence for starting, running, and stopping elevator cages and generating a normal speed command signal, while the other has functions of controlling the speeds of cages and generating a terminating floor deceleration command signal. In other words, the controlling functions of the elevator are distributed by a plurality of microcomputers.
FIG. 4 is a view of the entire arrangement of the conventional apparatus for controlling an elevator as described above. A rope 1 is engaged with a sheave 2, and a cage 3 is hung from one end of the rope 1 and a counterweight 4 is hung from the other end of the rope 1. An induction motor (IM) 5 is coupled through a shaft, shown, with the sheave 2 to drive it. A pulse generator (PG) 6 is coupled through a shaft with the motor 6 to generate pulses proportional to the moving distance of the cage 3 by the rotation of the motor. A counter 7 is electrically connected to the pulse generator 6 to count the number of pulses proportional to the number of revolutions of the motor from the pulse generator 6. A microcomputer system 8 inputs the pulse counted value 7a of the counter 7 and counts in a predetermined manner. A power converter 9 converts 3-phase a.c. from a 3-phase a.c. power supply 10 into power adapted for controlling an elevator speed. A command signal 8a is applied from the microcomputer system 8 to the power converter 9 to control the torque and the rotating speed of the motor 5. A terminating position detector 11 is provided in an elevator shaft (not shown) near a terminating floor 12 to generate an output signal 11a in cooperation with a cam 13 attached to the cage 3. The output signal 11a is inputted to the microcomputer system 8.
FIG. 5 is a block diagram showing the detail of a microcomputer system for use in the microcomputer system 8 as shown in FIG. 4. The microcomputer system 8 has a first microcomputer 80 and a second microcomputer 90. The first microcomputer 80 has a CPU 81, a ROM 83, a RAM 84, a regulating unit 85 to be described in detail later, an input port 86 and an output port 87 connected through a bus 82 to the CPU 81. The pulse counted value 7a of the counter 7 is inputted to the input port 86. The first microcomputer 80 sequentially calculates the running direction command, starting, running and stopping commands as well as generating the normal speed command signal of the cage 3.
The second microcomputer 90 has, similar to the first microcomputer 80, a CPU 91, a ROM 93, a RAM 94, a regulating unit 95, an input port 96 and an output port 97 connected through a bus 92 to the CPU 91. The pulse counted value 7a of the counter 7 and the output signal 11a of the terminating position detector 11 are inputted to the input port 96. The second microcomputer 90, when the normal speed command signal formed in the first microcomputer 80 is inputted, obtains a deviation from the pulse counted value 7a (i.e., a cage speed signal) proportional to the rotating speed of the motor 5, calculates (feedback calculates) a command to an exterior in accordance with the deviation, and generates a command signal 8a for controlling the rotating speed and the torque of the motor 5. The second microcomputer 90, inputs, when the cage 3 approaches the terminating floor 12, the output signal 11a of the terminating position detector 11, and executes the generation of a terminating floor deceleration command signal.
The above-described normal speed command signal calculated by the first microcomputer 80 is inputted to the CPU 91 of the second microcomputer 90 through a transmission interface (I/F) 100 for connecting the CPU 81 in the first microcomputer 80 to the CPU 91 in the second microcomputer 90. The command signal 8a generated in the CPU 91 is outputted through the output port 97 to the power converter 9.
The regulating units 85 and 95 externally set the set values and the regulating values of the first and second microcomputers 80 and 90, respectively, and are composed of rotary switches, dip switches or jumper plugs (not shown).
For example, the regulating unit 85 sets the acceleration and deceleration of a normal speed command signal, a rated speed, the number of stops of a building, a power supply frequency and/or the motor output of an elevator for the first microcomputer 80. The regulating unit 95 sets an acceleration at the time of decelerating, the terminating floor deceleration command signal, a rated speed, a power supply frequency, a motor output and/or the gain value of a feedback calculation for the second microcomputer 90. These set values and regulating values are not determined at the time of manufacture of the elevator but are set by an installation technician for the building into which it is to be installed. Particularly, the gain value and the acceleration of the feedback calculation are regulated by the installation technician while observing the riding comfort and the cage positioning accuracy at the floor of the elevator after installation.
Even if the conventional apparatus for controlling the elevator employs two microcomputers, the regulating units must be provided in the respective microcomputers, and it is economically disadvantageous.
The present invention has been made in view of the disadvantages described above, and has for its object to provide an apparatus for controlling an elevator which is inexpensive without need for a regulating unit.